Blasting explosive



Patented Feb. 1, 19 44 2,340,304 BLASTING EXPLOSIVE ,Willard de 0. Crater, Newark, Del., assignor to Hercules Powder Company, Wilmington, Del., a

corporation of Delaware No Drawing. Application October 3, 1939, Serial No. 297,654

1 Claim.

This invention relates to an improved blasting explosive and more particularly to a blasting explosive which includes optically inactive or I-inositol nitrate, preferably the hexanitrate, as an explosive ingredient.

It is well recognized in the art that the blasting explosives containing nitroglycerin, while in the main are satisfactory, are objectionable for a number of reasons, primarily in that the nitroglycerin explosives will freeze rendering the explosiveinsensitive. A further objection is that the nitroglycerin explosives cause severe headaches when worked with or handled. To overcome the disadvantage of explosives freezing, the art has used various substitutes for glycerin during the nitration procedure. Thus, it is possible to prepare liquid explosives from mixtures of glycerin, ethylene glycol, glycerol monochlorhydrin, diglycerol, etc., and lower the freezing point of the explosive. The use of these mixtures, while overcoming disadvantage of explosive freezing, presents additional disadvantages and problems to the art because nearly all of the glycerin substitutes when nitrated have a high negative oxygen balance. These negative oxygen balances present difllculties in formulating explosive compositions because the amount of carbonaceous material must be kept in a low ratio to the liquid explosive to obtain the proper and desired fume and burning properties and the correct explosive rates, strengths, sensitiveness and cartridge count.

It is the object of this invention to provide an explosive compound for use in preparing blasting explosives which is equally as strong as nitroglycerin and mixtures thereof with nitroglycerin substitutes and which has a high positive oxygen balance. A further object of this invention is to provide an explosive compound for use in blasting explosives from which may be produced a high strength explosive that has extremely good fume properties. A still further object of this invention is to provide an explosive compound which may be used in the preparation of non-headache powders'.' A still further object is to produce a dynamite which may contain a high percentage of liquid explosive and which has a high ratio of absorbent material to liquid explosives with a comparable oxygen balance. A still further object of this invention is to produce a high strength explosive with an improved oxygen balance. Other objects will appear hereinafter.

Now in accordance with this invention I have found that by the use of nitrated I-inositol I may produce an explosive which has a greatly improved oxygen balance, and is equal in strength, rate, and sensitiveness to regular nitroglycerin dynamites. This improved explosive compound may also be compounded into non-headache producing powders.

In particular I have found that by the incorporation oi I-inositol hexanitrate in explosives containing a high percentage of nitroglycerin or mixtures thereof with the nitroglycerin substitutes, I may produce a high explosive with good fume properties, proper combustion qualities and which will be low freezing or non-freezing. Nonheadache powders may be produced by using as the active explosive ingredient I-inositol hexanitrate alone or in admixture with other solid explosives as pentaerythritol tetranitrate, trinitrotoluene. nitrostarch, cyclotrimethylene-trinitramine, etc.

My new explosive compound is prepared from I-inositol, a polyhydric alcohol, belonging to the cycloses, a group of compounds widely distributed in nature, that are intermediate between the aliphatic polyhydroxy alcohols and the phenols. Thus inositol forms a connecting link between the sugars and the aromatic benzene ring derivatives and may be regarded chemically as derivatives of hexamethylene or hexahydrobenzene. There are several isomers of inositol, or s-hexahydroxy cycle-hexane, the most common being optically inactive or I-inositol and the optically active or dor l-inositol.

It is to be noted that the nitration products of the inactive-inositol and the active-inositol are completely difierent from each other. The I-inositol nitrate is a solid while the active inositol nitrate is a liquid. The uses and preparation of active inositol have been disclosed and claimed in my prior U. S. Patents No. 1,850,225. The present application deals with the inactive inositol nitrate which I have found when formu lated in dynamites and gelatins gives explosives whichhave many advantages and superior properties.

The nitration of I-inositol to I-inositol hexaner.

nitrate may be carried out in the following man- To 500 grams of mixed acid, having an approximate composition of 50% sulfuric acid and 50%nitric acid, contained in a suitable-nitrating apparatus and under agitation. 100 grams of I-inpsitol are added gradually at such a rate as to maintain the temperature of nitration at about 45 to 50 F., and after all the inositol has been added the agitation is continued for about 30 minutes.

The nitrated I-inositol is separated from the waste acid byallowing the charge to stand and skimming oil! the nitrated material, or preferably by either filtering or centrifuging. separation is complete, the nitrate'd product is washed first with cold water, then with water at about 110 F. followed by a dilute sodium carbonate wash at about 110 F. A fresh water wash is then given, followed by a second sodium carbonate wash. After the second soda-wash the I- inositol hexanitrate may, if desired, be dissolved in methyl alcohol and recrystallized.

The nitration product produced is I-inositol hexanitrate and this solid is stable under normal conditions but has explosive characteristics which make it usefulin formulating explosives. The solid I-inositol hexanitrate may be incorporated as the only explosive ingredient or may be incorpoi-ated in explosives having other explosive ingredients present.

The incorporation of I-inositol nitrate in an explosive has alternatively been accomplished by nitrating the I-inositol in admixture with glycerin, ethylene glycol, glycerol monochlorohydrin, diglycerol, etc., or mixtures of two or more of these compounds. The nitration, separatiomand After the washing was accomplished by the conventional methods now used for the manufacture of nitroglycerin.

In order to specifically point out the method of conitration the following example is given in which an admixture of I-inositol, ethylene glycol,

and glycerin was nitrated.

To 500 parts by weight of mixed acid containing approximately 55% nitric acid and sulfuric acid were slowly added 120 parts by weight of a mixture consisting of 40% ethylene glycol, 40% I-inositol and 20% glycerin, the rate of addition being such, as to maintain the desired temperature of nitration, say in the neighborhood of 40 F. After nitration is complete, the charge is run into the separator and on standing the nitrated product rises to the surface of the acid. Then after separation is complete, the waste acid is drawn off by means of a suitable spigot, and the nitroglycerin/nitroglycol/nitro-I- inositol mixture is run into a pre-wash tank where it is washed with water by agitating with air. Then the air is shut oil and the charge allowed to settle out of the'wash water. After settling is complete, the nitroglycerin mixture is run into a solution of soda ash which is agitated by air. One or more soda washes may be given to complete the stabilization. After the neutralization procedure the charge is then ready for use.

Wherein this specification and claims the term nitroglycerin is used to designate the explosive oil, it should be understood that by the term nitroglycerin is meant either this compound by itself or with the addition or partial substitution of any of the commonly used freezing point depressants. The term nitroglycerin as here described is well accepted in the explosive art.

The product obtained by the above co-nitraasi e tion is a suitable explosive ingredient for use in the manufacture of dynamite, particularly those powders which contain a high percentage of nitroglycerin.

The I-inositol hexanitrate produced by either of theabove nitrations has a positive oxygen balance of +10.66%, and this materially aids in producing exposive compositions which exhibit good fume properties and also allows the formulation of explosiveshaving desirable combustion characteristics. By way of comparison the following tabulation, given in Table 1, shows the oxygen balance of the various explosive compounds commonly used in dynamite.

Table 1 Compound Per cent Dynamite nitroootton Pentaerythritol tetranitrate'. -Z Nitrostarch. 37. 00

It will be apparent to those versed in the art of explosives manufacture that by using such an explosive ingredient as I-inositol hexanitrate with the high positive oxygen balance it is possible to improve the ox: gen balance of certain high-grade explosives, or to retain their present oxygen balance and at the same time add more absorbent carbonaceous material to increase their resistance to leakiness. The following examples given in Table 2 will serve to illustrate this point:

In Table 2 the term oxygen balance is abbreviated O. B.

. Table 2 Sample No. Ingredients Nitroalucerin composition Per cent 0. B. Per cent 0.B. 2 iti i-"fia" e y ene yco tgaztlla O. B. o! mixture 60 g0? hltl1l0 gllheriz;i::::::

e tm.-i. .fif. .f. 60 40% I-inositol hexanitrate 0. B. of m is +4.77," Bog 21311.3) 1 nitrate (0. B.

. 20 +9. 32 2o 9. 32 Wood pulp (0. B. --l40) 19 26. 60 19 $0. 60 Chalk 1 1 Oxygen balance of mixed explosives 16.0 -14. 5

1 Commercial product, 0. P. material has an O. B. oi 47.1%.

To further show the desirability of using I- inositol hexanitrate, numerous representative dynamites containing as their explosive constituent a, mixture of 40% ethylene glycol dinitrate,

2,340,304 3 Table 3 Sample No.

l i i oi'i i rti 40.0 13.0 35.65 25.00 Blend No.2 %'1-?Z}3"'iriap 3 ens y NH:HO| (density .98) 11 gag N No! 0:50 0:50 4.50 4.50 7.00 1.00 4.00 4.00 1.00 1.00 0 gen balan0e +d +8.6 +6.7 +7.4 +415 +7, 0531a arm 5011.5 104 104 100 109 04 03 Rate Ill-I860 4,033 4,930 ,002 2,988 0,044 5,531 Sengitlveness 45" 40" 36" 28" 16" 4" Wwt. strength, percent 40.0 41- The foregoing results show that the (1) count, (2) sensitiveness, (3) rate and (4) strength of explosives using I-inositol hexanitrate are comparable to other explosives and that by using I-inositol hexanitrate the oxygen balance of explosives is easier to properly control.-

The art is continually striving for an improvement of the oxygen balance of explosives as by this means the complete burning of the ingredients is insured. The complete burning of ingredients which make up the explosive mixture prevents the formation of poisonous fumes and is therefore very necessary to accurately control.

In the above examples I have shown the preparation of powders in which the I-inositol hexanitrate is admixed with liquid explosives of the nitroglycerin type. An alternative type powder which may be prepared with I-inositol hexanitrate is a non-freezing, non-headache powder. Thus, since I-inositol hexanitrate is a. solid, I may compound the type powders given below in Table 4.

Table 4 Ingredients No. 1 No. 2 N o. 3

Per cent I-inositrol hexanitratc. 16.0 Dinitrotoluene Pentaerythritol tetranitra 5.0 Ammonium nitrate 60. 0 65.0 67.0 Sodium nitrate 5.0 7. 5 5.0 Wood pulp 6.0 Ground coal 7. 0 Ivory meal 7. 5 Chalk 0. 5

A further alternative use of I-inositol hexanitrate in explosives which I have found gives powders that are very useful and easily prepared is the use of I-inositol hexanitrate as a coating for ammonium nitrate used in various powder formulation.

Thus, to obtain an intimate contact with the ammonium nitrate the I-inositol hexanitrate may be dissolved in a suitable solvent, for example acetone, and this solution sprayed on the ammonium nitrate, or the ammonium nitrate may be coated with the I-inositol hexanitrate in any other suitable manner.

This coated ammonium nitrate may be used alone as a blasting explosive, or it may be used in admixture with other ingredients to prepare various explosive compositions. Because of its positive oxygen balance I-inositol hexanitrate Per cent Per cent Coated ammonium nitrate 'lrinitrotoluene. Sodium nitrate Ivory meal Wood pulp Engine oil Fen-o silicon Ground coal The powder compositions given in the above tables adequately point out the various type explosives in which I may use I-inositol hexanitrate and also show the advantages realized when this solid non-freezing, non-headache ingredient is used. I

The above explosive compositions serve as examples, and it is to be understood that my invention is not limited to these formulae and ingredients. Without departing from the spirit of the invention, it will be apparent to any one skilled in the art that both the amount and ingredients used may be varied over a wide range to produce powders of difierent characteristics to meet various blasting requirements.

It is well known in the art that if the ingredients are properly proportioned, it is possible to obtain even a zero oxygen balance but this cannot always be accomplished and still maintain an explosive which has the necessary strength, rate, sensitiveness, and count. Thus, when the amount of liquid explosive is cut down to obtain an improved oxygen balance, the strength, sensitiveness and rate are altered, while if the carbonaceous material is decreased to aid the oxygen balance, the count of the finished explosive is altered. The ideal means of improving the oxygen balance is therefore to use ingredients which have an oxygen balance that offsets the necessary alteration of the formula being used.

The explosive ingredient I-inositol hexanitrate which I have used in dynamite formulation has an oxygen balance that allows the formulation of dynamltes in a manner which allows the art What I claim and desire to protect by Letters to produce explosives having an oxygen balance Patent is: which approaches zero. A commercial blasting explosive comprising an It will 'be understood that the details and exadmixture oi! I-inositol hexanitrate, nitroglycerin, amples hereinbefore set forth are illustrative 5 a. carbonaceous material and an oxidizing salt. only, and that the invention as broadly described and claimed is in no way limited thereby. WILLARD m: C. CRATER. 

